4d slides Flashcards
what does interphase include
cell growth and copying of chromosomes in preparation for cell division
what subphases can interphase be divided into
G1 (Gap 1), S (synthesis), G2
during which phase are chromosomes duplicated
only during S phase
mitosis produce what
cell division that results in diploid daughter cells with identical genetic information, DNA
meiosis produces what
a special type of division that produces haploid non identical daughter cells (gametes)
G2 interphase
Chromosomes are uncondensed and have just duplicated in S phase
prophase
Chromosomes condense and consist of two sister chromatids; mitotic spindle which consists of centrosomes and microtubules begins to form and centrosomes move away from each other
prometaphase
chromosomes condense further
metaphase
centrosomes at opposite poles of the cell; chromosomes arrive at metaphase plate
anaphase
Sister chromatids are split and become independent chromosomes; chromosomes move toward opposite ends of the cell; two ends of the cell will have identical collections of chromosomes
telophase
2 daughter nuclei form in cell; the nuclear envelope arises from fragments of parent cell nuclear envelope and endomembrane system
cytokinesis
division of cytoplasm
which phases are often shown together
telophase and cytokinesis
what is gene expression
transcription and translation
why does almost all gene expression stop during mitosis?
The DNA is condensed and not available to cellular machinery to carry out gene expression.
what does stopping gene expression present
interference with mitosis and helps ensure accurate segregation of genetic material to daughter cells
what happens to chromosomes in G2 of interphase
chromosomes are uncondensed and have just duplicated in S phase
in animal cells, cytokines occurs by a process known as what and what does it form
cleavage forming a cleavage furrow
in plant cells what forms during cytokinesis
cell plate
cleavage
cytokinesis in animal cells characterized by pinching of the membrane
cleavage furrow
shallow groove in the cell surface near old metaphase plate
cell plate
membrane bounded, flattened ac in the middle of a dividing plant cell, inside which the new cell wall forms during cytokinesis
binary fission
asexual reproduction in unicellular organisms where cells grow to double their size and then divide
mitosis is involved in unicellular ________ but not in ________
eukaryotes; prokaryotes
what type of DNA do bacteria have
single circular DNA molecule
what did mitosis evolve from
binary fission
how is the eukaryotic cell cycle regulated
by signaling molecules
cell cycle control system
clinically operating set of molecules in eukaryotic cells that triggers and coordinates events in the cell cycle
what can checkpoint signals include
growth factors
growth factor
protein that stimulates other cells to divide
anchorage dependesnce
for most anmals cells to divide, the cells must be attached to something (in animal cells)
density of dependent inhibition
crowded cells stop growing (terminates division)
biding of surface protein between cells sends a signal to inhibit what
cell division
what do cancer cells not exhbiti
density dependent inhibition nor must they be attached to a substrate
what do cancer cells not hede
normal signals that reglate cell cycyle
what can cancer cells grow without
growth factors
are sister chromatids identical
yes
homologous chromosomes compared to sister chromatds
homologous chromosomes are similar but not exact copies like sister chromatids
what is chromatin composed of
DNA wrapped around by histone proteins
what level of protein structure is directly affected by a missense mutation
primary
what does a nonsense mutation terminate
translation
translation
synthesis of protein based on a codon
anaphase
sister chromatids are being pulled away from each other
can eukaryotes be unicellular
yes
are majority of eukaryotes unicellular
yes
why dont prokaryotes have mitochondria
because they do not have membrane bound organelles
